2. T YPES OF C HEMICAL R EACTIONS

3. Although there are MILLIONS of possible chemical reactions, we are able to use patterns to identify/predict some general TYPES of reactions.

4. T YPES OF C HEMICAL R EACTIONS SynthesisDecomposition Single Displacement Double Displacement Combustion

5. S YNTHESIS R EACTIONS The direct combination of 2 substances (elements or compounds) to form a compound. General equation: A + B → AB A and B can be elements or compounds, AB is a compound.

6. EXAMPLES OF SYNTHESIS Rxns: Video: Video: P 4 (s) + 5O 2 (g)  2P 2 O 5 Video: Video: 2Na (s) + Cl 2 (g)  2NaCl (s) Video: Video: 2Al (s) + 3I 2 (g)  2AlI 3

7. D ECOMPOSITION REACTIONS

8. Decomposition Reactions - The splitting up of a larger molecule into simpler substances (elements or compounds). - often require heat, light or electricity General Equation: AB→ A + B AB is a compound, A and B can be elements or compounds

9. E XAMPLES OF D ECOMPOSITION R XNS : Electrolysis of water: 2 H 2 O  2H 2 + O 2 Video: Video: Nitrogen triiodide decomposing: 2NI 3  N 2 + 3I 2 Video: Video: Breaking down of sugar C 12 H 22 O 11  12C (s) + 11H 2 O Electrolysis: the decomposition of a compound by an electric current

10. S INGLE D ISPLACEMENT -one element takes the place of (displaces) another element in a compound -usually metals displace metals, and non metals displace non metals

11. General equation: A+ BC → B + AC (A is a metal) OR N + BC → B + CN (N is a non-metal) A, B, and N are elements/diatomic molecules. BC, AC and CN are compounds.

12. EXAMPLES of Single Displacement Rxns: Video: Video: 2Mg (s) + CO 2 (s)  C (s) + 2MgO (s) Video: Video: Cu (s) + 2AgNO 3 (aq)  Cu(NO 3 ) 2 (aq) + 2Ag (s) Video: Video: thermite (steel making) Fe 2 O 3 (s) + 2Al (s)  2Fe (s) + Al 2 O 3 (s)

13. D OUBLE D ISPLACEMENT -Involves the displacement of “partners” -the cations of two compounds exchange places, elements in different compounds displace each other or exchange places. - a precipitate, a gas or a molecular compound is usually formed

14. General equation: AB + CD → AD+ CB A,C = metals (polyatomic ions or atoms) B,D = non metals (polyatomic ions or atoms) *Remember, metals can only switch with metals, and non-metals can only switch with non-metals!

15. E XAMPLES OF D OUBLE D ISPLACEMENT R XNS : Video: 2NaOH (aq) + Cu(NO 3 ) 2 (aq)  Cu(OH) 2 (s) + 2NaNO 3 (aq) Colour of precipitate: light blue Video: 2NaI (aq) + Pb(NO 3 ) 2 (aq)  PbI 2 (s) + 2NaNO 3 (aq) Colour of precipitate: yellow

16. C OMBUSTION

17. A chemical reaction in which a substance (often hydrocarbons like propane (C3H8), methane (CH4) and kerosene (C10H22) ) reacts rapidly with OXYGEN and releases heat and light energy.

18. The word equation for the COMPLETE COMBUSTION of a hydrocarbon: Hydrocarbon + Oxygen →Carbon Dioxide+Water Vapour + Energy (light & heat) The general equation: C x H y +O 2 →CO 2 +H 2 O Ex: Propane in a BBQ- C 3 H 8 +5O 2 →3CO 2 +4H 2 O

19. Incomplete Combustion occurs when there is not enough O 2 available for complete combustion produces CO, C, CO 2, and H 2 O vapour